title: Recovery of microbial diversity and activity during bioremediation following chemical oxidation of diesel contaminated soils.
abstract: To improve the coupling of in situ chemical oxidation and in situ bioremediation, a systematic analysis was performed of the effect of chemical oxidation with Fenton's reagent, modified Fenton's reagent, permanganate, or persulfate, on microbial diversity and activity during 8 weeks of incubation in two diesel-contaminated soils (peat and fill). Chemical oxidant and soil type affected the microbial community diversity and biodegradation activity; however, this was only observed following treatment with Fenton's reagent and modified Fenton's reagent, and in the biotic control without oxidation. Differences in the highest overall removal efficiencies of 69 % for peat (biotic control) and 59 % for fill (Fenton's reagent) were partially explained by changes in contaminant soil properties upon oxidation. Molecular analysis of 16S rRNA and alkane monooxygenase (alkB) gene abundances indicated that oxidation with Fenton's reagent and modified Fenton's reagent negatively affected microbial abundance. However, regeneration occurred, and final relative alkB abundances were 1-2 orders of magnitude higher in chemically treated microcosms than in the biotic control. 16S rRNA gene fragment fingerprinting with DGGE and prominent band sequencing illuminated microbial community composition and diversity differences between treatments and identified a variety of phylotypes within Alpha-, Beta-, and Gammaproteobacteria. Understanding microbial community dynamics during coupled chemical oxidation and bioremediation is integral to improved biphasic field application.
authors.affiliation: Department of Environmental Technology, Wageningen University, PO Box 17, 6700 EV, Wageningen, The Netherlands, Nora.Sutton@wur.nl.
authors.forename: Nora B
authors.initials: NB
authors.lastname: Sutton
authors.forename: Alette A M
authors.initials: AA
authors.lastname: Langenhoff
authors.forename: Daniel Hidalgo
authors.initials: DH
authors.lastname: Lasso
authors.forename: Bas
authors.initials: B
authors.lastname: van der Zaan
authors.forename: Pauline
authors.initials: P
authors.lastname: van Gaans
authors.forename: Farai
authors.initials: F
authors.lastname: Maphosa
authors.forename: Hauke
authors.initials: H
authors.lastname: Smidt
authors.forename: Tim
authors.initials: T
authors.lastname: Grotenhuis
authors.forename: Huub H M
authors.initials: HH
authors.lastname: Rijnaarts
mesh_terms: D001419:Bacteria / Q000145:classification* / Q000235:genetics; D001673:Biodegradation, Environmental; D058448:Biota; D016000:Cluster Analysis; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005742:Gasoline; D008969:Molecular Sequence Data; D010084:Oxidation-Reduction; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005742:Gasoline; D012336:RNA, Ribosomal, 16S; D012987:Soil; D012989:Soil Pollutants